Dynamic read only column format

I am creating dynamic column the following way:

                Dim TotalColumn As New GridNumericColumn()
                grdContingentDevelopment.MasterTableView.Columns.Add(TotalColumn)
                TotalColumn.DataField = "Total"
                TotalColumn.HeaderText = "Total"
                TotalColumn.SortExpression = "Total"
                TotalColumn.HeaderStyle.HorizontalAlign = HorizontalAlign.Left
                TotalColumn.ItemStyle.HorizontalAlign = HorizontalAlign.Left               
                TotalColumn.DataFormatString = "{0:N2}"
                TotalColumn.HeaderStyle.Width = 90
                TotalColumn.ItemStyle.Width = 90
                TotalColumn.ItemStyle.Font.Bold = True

That works fine, however if i add: TotalColumn.ReadOnly = True, most of formats such as DataFormatString or HorizontalAlign stop working

Any ideas?